Piston valve



Patented July 3, 192s.

EMIL ALLZEIIL,` OF KONIGSBEG, GERMANY.`

PIs'roN VALVE. i i

Application led February 26, 1926, Serial No. `90,83'7Qand in lGermany May24, 1924.

The pre-sent invention relates to piston valves for steam engines principally designed to be used in connection with loco motives, and has for an object to provide an automatic equalization piston valve having two different and distinct sets of steam passages in each piston head designed to allow the admission of steam from the steam inlet chamber into the steam cylinder,- also to equalize the diiierence between the pressure in the exhaust chamber and the pressure in said inlet chamber, when the pressure in the latter sinks below a predetermined minimum and adapted to permanently maintain a communication between the exhaust chambers, the inlet space and both sides of the cylinder when the shut off.

Another :important object of' the inven-` tion residesin the provision of independent preferably spring actuated means `for each piston head serving for 'closing the pas* sages in said heads when the pressure in the steam inlet chamber surpasses a predetermined maximum. y

It is also amongst the desideratums of the Vinvention to provide a piston valve `wherein the steam passages for equalizing the differ-- ence o'f pressure are essentially formed in a same plane as the inlet :channels or steam passages of said piston valve to the cylinder,

whereby when the engine runs idle, as when the locomotive runs down an incline at high speed, free equalizing pressure is created, absolutely preventing the sucking in ol smoke, dirt and the like into the inlet chamber, through the different passages in the piston valve. d

`Otherimportant. objects of. the invention will be in part obvious and in part pointed out hereinafter.

ln order that` the invention and its mode of operation maybe readily understood by those skilled in the art to which it` appertains, l have in the accompanying illustrative drawings `and in the detailed following description based thereupon, `set out one possible embodiment of the invention.

In these drawings is illustrated a vertical cross section throughy the improvedequalizing piston'valve mounted `on an engine cylinder, a portion of which isalso shown in cross section. y. i

Havingmore particular reference tothe drawings, where-1n like characters of refer*m operating medium is` ence will designate corresponding parts throughout, I have shown an engine cylinder a of the type generally used in locomotives, and having a piston s mounted foi-movement therein. Secured in the usual manner to the cylinder a and having communication therewith by means ofthe combined intake and exhaust ports e' formedat each `end of said cylinder is a valve casing g. This valve casing has its opposed end opened to form the exhaust chambers c ,communicating with each other vthrough a pipe (not shown) or any other suitable and convenient means known `in the art. The `central portion of the valve `casing g is provided with an annular steam inlet chamber b communicating with the supply pipe la.

Mounted to reciprocate within the casing g is the piston rod lr carrying the Valve piston heads z arranged adjacent the combined inlet and exhaust ports z' and adapted to control the flow of lmot-or fluid `or steam coming from thc 'niet chamber b, to said ports as well as to permit steam to pass to the exhaust chambers-c.

Formed within said piston heads is a set of steampassages f terminating at one end in an annular channel having at times commui'iication with the intake and exhaust ports 1I for the admission Aof motor fluid or steam from the inlet chamber Z) into the cylinder a. Another similar set `of concentrically arranged steam passages e is also formed in the piston heads 71 and extend completely therethrough. The steam passages e form means of' communicationbetween the inlet chamber and the exhaust chambers c per-` mitting` the equalization of pressure in said chambers.

i For the purpose of controlling the amount of steam passing through the diierent passages e and f, I provide for each piston head 7i an independently operated valve d shifts ably mounted upon the piston rod r, and adaptedto contact with its respective piston head. The contacting face of the valves d are preferably provided with a plurality of suitable packing rings p, so that a irm and tight connection between each valve and its respective piston head will be had. The valves (l are normally maintained `open or away from the pistonheadsh by .any suitable or` convenient lneans, but preferably,A as 'shown inthe drawings by a spring' m ref` tained within each valve on the pister-i red fr.

The inward movements of the valves d are limited by collars d formed with or otherwise secured to the piston rod 71.

From the foregoing description, it will be obvious to those skilled in the art, that the motor fluid or steam entering the inlet chamber b through the supply pipe k', will alternately enter into each end of the cylinder e. through the ste-am passages f formed in each reciprocating piston head k. when the latter passes over its adjacentport z'. Likewise, the exhaust steam will alternately leave through the portse'Y from the opposite ends ot the cylinder a. into the adjacent exhaust chambers c wherein the exhaust will meet with the steam passing from the openings c of the piston heads.

It will also be understood that the valves Z are kept or niaintained in open position by means oi the springs fm as long as the pressure in the steam inlet chamber does not become too high. However, it is obvious that when the pressure does increase and become. too high the valves will be forced outwardly and close the passages in the piston heads t, but as soon as thc pressure again reduces the valves (l will be auto matically opened through the force and action ot the spring m.

It will also be understood that as long as the valves (Z are kept away from their piston heads z the passages c will remain open and will effect a pressure equalization between the exhaust spaces c and the steam inlet chamber b. This communication between the exhaust and inlet chambers will also take place during part ot the stroke, while the steam passages f will be closed because of the same being covered by the wall ot the valve casing (,f in which the piston heads i are reciprocating.

Because of 'its simple construction, my improved piston valve is very reliable in service and cheap to manufacture and will also pen mit an easy replacement ot parts.

It will be understood by those skilled in the art that, by the special arrangement and construction ot the device with its valves d operating independently from each other, I have realized a `great advantage in that should one et the valves be damaged or otherwise become inoperative the other or remaining valve will effect the pressure equalization, which will not in any manner be hindered.

bfianiliestly, the construction shown is capable ot considerable modiication and such moditication as is within the spirit of my claims, I consider within the scope of my invention.

I claim:

1. A piston valve for steam engines comprising in combination with a cylinder a valve casing having steam inlet and exhaust chambers therein and communicating with both sides of the cylinder, a double headed piston having two distinct sets of steam passages formed therein and reciprocatingr in said valve casing; one set of said passages for admitting steam :trom the steam inlet chamber into the cylinder, the second for equalizing the difference between the pres` sure in the exhaust chambers and the pressure in the steam inlet chamber when the pressure vin the latter sinks below a predetermined minimum, said two sets ot steam passages adapted to permanently maintain the communication between the exhaust chambers, the inlet chamber and both sides ol the cylinder when the steam shut oil, and independent means, for each piston head, serving Vfor closing the passages in the piston heads when the pressure in the steam inlet chamber surpasses a predetermined maximum.

2. A piston valve tor steam engines com prising in combination with a cylinder, a valve casing having a steam inlet and cxhaust chan'ibers therein and communicating with both sides of the cylinder, a double headed piston having two distinct sets of steam passages formed therein and reciprocating in said valve casing; one set o'f said passages for admitting steam from the steam inlet chamber into the cylinder, the second for equalizing the difference between the pressure in the exhaust chambers and the pressure in the steam inlet chamberwhen the pressure in the latter sinks below ay predetermined minimum, said two sets ot' steam passages adapted to permanently maintain the communication between the exhaust chambers, the inlet chamber and both sides ot the cylinder when the steam is shut oil and communicating with both sides ot the cylinder. and an independent spring actuated valve for ea'ch piston head servingr for closing thc passages in the piston heads when the pressure in the steam inlet chamber surpasses a predetermined maximum.

A piston valvetor steam engines, con prising` in combination with a cylinder, .i valve casing mounted on said cylinder and havin g communication therewith, said casing carrying` an exhaust chamber at each ot its opposite ends and a steam inlet chamber formed therelictween, a double headed piston reciprocating in said casing, each head of said piston having two sets of steam passages. one communicating with the steam in let chamber and the cylinder and the other communicating the steam inlet chamber with the exhaust. chambers. and indepcndentiy operated valves adapted to have contact at times with such piston head for closing said passages.

In testimony whereof I ailx my signature.

EMIL ALLZEIT. 

